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[linux-2.6.32.60-moxart.git] / kernel / params.c
blobd656c276508de6a9bbeb62407b59e477ff7ff61e
1 /* Helpers for initial module or kernel cmdline parsing
2 Copyright (C) 2001 Rusty Russell.
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 #include <linux/moduleparam.h>
19 #include <linux/kernel.h>
20 #include <linux/string.h>
21 #include <linux/errno.h>
22 #include <linux/module.h>
23 #include <linux/device.h>
24 #include <linux/err.h>
25 #include <linux/slab.h>
26 #include <linux/ctype.h>
28 #if 0
29 #define DEBUGP printk
30 #else
31 #define DEBUGP(fmt, a...)
32 #endif
34 static inline char dash2underscore(char c)
36 if (c == '-')
37 return '_';
38 return c;
41 static inline int parameq(const char *input, const char *paramname)
43 unsigned int i;
44 for (i = 0; dash2underscore(input[i]) == paramname[i]; i++)
45 if (input[i] == '\0')
46 return 1;
47 return 0;
50 static int parse_one(char *param,
51 char *val,
52 struct kernel_param *params,
53 unsigned num_params,
54 int (*handle_unknown)(char *param, char *val))
56 unsigned int i;
58 /* Find parameter */
59 for (i = 0; i < num_params; i++) {
60 if (parameq(param, params[i].name)) {
61 DEBUGP("They are equal! Calling %p\n",
62 params[i].set);
63 return params[i].set(val, &params[i]);
67 if (handle_unknown) {
68 DEBUGP("Unknown argument: calling %p\n", handle_unknown);
69 return handle_unknown(param, val);
72 DEBUGP("Unknown argument `%s'\n", param);
73 return -ENOENT;
76 /* You can use " around spaces, but can't escape ". */
77 /* Hyphens and underscores equivalent in parameter names. */
78 static char *next_arg(char *args, char **param, char **val)
80 unsigned int i, equals = 0;
81 int in_quote = 0, quoted = 0;
82 char *next;
84 if (*args == '"') {
85 args++;
86 in_quote = 1;
87 quoted = 1;
90 for (i = 0; args[i]; i++) {
91 if (isspace(args[i]) && !in_quote)
92 break;
93 if (equals == 0) {
94 if (args[i] == '=')
95 equals = i;
97 if (args[i] == '"')
98 in_quote = !in_quote;
101 *param = args;
102 if (!equals)
103 *val = NULL;
104 else {
105 args[equals] = '\0';
106 *val = args + equals + 1;
108 /* Don't include quotes in value. */
109 if (**val == '"') {
110 (*val)++;
111 if (args[i-1] == '"')
112 args[i-1] = '\0';
114 if (quoted && args[i-1] == '"')
115 args[i-1] = '\0';
118 if (args[i]) {
119 args[i] = '\0';
120 next = args + i + 1;
121 } else
122 next = args + i;
124 /* Chew up trailing spaces. */
125 while (isspace(*next))
126 next++;
127 return next;
130 /* Args looks like "foo=bar,bar2 baz=fuz wiz". */
131 int parse_args(const char *name,
132 char *args,
133 struct kernel_param *params,
134 unsigned num,
135 int (*unknown)(char *param, char *val))
137 char *param, *val;
139 DEBUGP("Parsing ARGS: %s\n", args);
141 /* Chew leading spaces */
142 while (isspace(*args))
143 args++;
145 while (*args) {
146 int ret;
147 int irq_was_disabled;
149 args = next_arg(args, &param, &val);
150 irq_was_disabled = irqs_disabled();
151 ret = parse_one(param, val, params, num, unknown);
152 if (irq_was_disabled && !irqs_disabled()) {
153 printk(KERN_WARNING "parse_args(): option '%s' enabled "
154 "irq's!\n", param);
156 switch (ret) {
157 case -ENOENT:
158 printk(KERN_ERR "%s: Unknown parameter `%s'\n",
159 name, param);
160 return ret;
161 case -ENOSPC:
162 printk(KERN_ERR
163 "%s: `%s' too large for parameter `%s'\n",
164 name, val ?: "", param);
165 return ret;
166 case 0:
167 break;
168 default:
169 printk(KERN_ERR
170 "%s: `%s' invalid for parameter `%s'\n",
171 name, val ?: "", param);
172 return ret;
176 /* All parsed OK. */
177 return 0;
180 /* Lazy bastard, eh? */
181 #define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn) \
182 int param_set_##name(const char *val, struct kernel_param *kp) \
184 tmptype l; \
185 int ret; \
187 if (!val) return -EINVAL; \
188 ret = strtolfn(val, 0, &l); \
189 if (ret == -EINVAL || ((type)l != l)) \
190 return -EINVAL; \
191 *((type *)kp->arg) = l; \
192 return 0; \
194 int param_get_##name(char *buffer, struct kernel_param *kp) \
196 return sprintf(buffer, format, *((type *)kp->arg)); \
199 STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, strict_strtoul);
200 STANDARD_PARAM_DEF(short, short, "%hi", long, strict_strtol);
201 STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, strict_strtoul);
202 STANDARD_PARAM_DEF(int, int, "%i", long, strict_strtol);
203 STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, strict_strtoul);
204 STANDARD_PARAM_DEF(long, long, "%li", long, strict_strtol);
205 STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, strict_strtoul);
207 int param_set_charp(const char *val, struct kernel_param *kp)
209 if (!val) {
210 printk(KERN_ERR "%s: string parameter expected\n",
211 kp->name);
212 return -EINVAL;
215 if (strlen(val) > 1024) {
216 printk(KERN_ERR "%s: string parameter too long\n",
217 kp->name);
218 return -ENOSPC;
221 /* This is a hack. We can't need to strdup in early boot, and we
222 * don't need to; this mangled commandline is preserved. */
223 if (slab_is_available()) {
224 *(char **)kp->arg = kstrdup(val, GFP_KERNEL);
225 if (!*(char **)kp->arg)
226 return -ENOMEM;
227 } else
228 *(const char **)kp->arg = val;
230 return 0;
233 int param_get_charp(char *buffer, struct kernel_param *kp)
235 return sprintf(buffer, "%s", *((char **)kp->arg));
238 /* Actually could be a bool or an int, for historical reasons. */
239 int param_set_bool(const char *val, struct kernel_param *kp)
241 bool v;
243 /* No equals means "set"... */
244 if (!val) val = "1";
246 /* One of =[yYnN01] */
247 switch (val[0]) {
248 case 'y': case 'Y': case '1':
249 v = true;
250 break;
251 case 'n': case 'N': case '0':
252 v = false;
253 break;
254 default:
255 return -EINVAL;
258 if (kp->flags & KPARAM_ISBOOL)
259 *(bool *)kp->arg = v;
260 else
261 *(int *)kp->arg = v;
262 return 0;
265 int param_get_bool(char *buffer, struct kernel_param *kp)
267 bool val;
268 if (kp->flags & KPARAM_ISBOOL)
269 val = *(bool *)kp->arg;
270 else
271 val = *(int *)kp->arg;
273 /* Y and N chosen as being relatively non-coder friendly */
274 return sprintf(buffer, "%c", val ? 'Y' : 'N');
277 /* This one must be bool. */
278 int param_set_invbool(const char *val, struct kernel_param *kp)
280 int ret;
281 bool boolval;
282 struct kernel_param dummy;
284 dummy.arg = &boolval;
285 dummy.flags = KPARAM_ISBOOL;
286 ret = param_set_bool(val, &dummy);
287 if (ret == 0)
288 *(bool *)kp->arg = !boolval;
289 return ret;
292 int param_get_invbool(char *buffer, struct kernel_param *kp)
294 return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y');
297 /* We break the rule and mangle the string. */
298 static int param_array(const char *name,
299 const char *val,
300 unsigned int min, unsigned int max,
301 void *elem, int elemsize,
302 int (*set)(const char *, struct kernel_param *kp),
303 u16 flags,
304 unsigned int *num)
306 int ret;
307 struct kernel_param kp;
308 char save;
310 /* Get the name right for errors. */
311 kp.name = name;
312 kp.arg = elem;
313 kp.flags = flags;
315 /* No equals sign? */
316 if (!val) {
317 printk(KERN_ERR "%s: expects arguments\n", name);
318 return -EINVAL;
321 *num = 0;
322 /* We expect a comma-separated list of values. */
323 do {
324 int len;
326 if (*num == max) {
327 printk(KERN_ERR "%s: can only take %i arguments\n",
328 name, max);
329 return -EINVAL;
331 len = strcspn(val, ",");
333 /* nul-terminate and parse */
334 save = val[len];
335 ((char *)val)[len] = '\0';
336 ret = set(val, &kp);
338 if (ret != 0)
339 return ret;
340 kp.arg += elemsize;
341 val += len+1;
342 (*num)++;
343 } while (save == ',');
345 if (*num < min) {
346 printk(KERN_ERR "%s: needs at least %i arguments\n",
347 name, min);
348 return -EINVAL;
350 return 0;
353 int param_array_set(const char *val, struct kernel_param *kp)
355 const struct kparam_array *arr = kp->arr;
356 unsigned int temp_num;
358 return param_array(kp->name, val, 1, arr->max, arr->elem,
359 arr->elemsize, arr->set, kp->flags,
360 arr->num ?: &temp_num);
363 int param_array_get(char *buffer, struct kernel_param *kp)
365 int i, off, ret;
366 const struct kparam_array *arr = kp->arr;
367 struct kernel_param p;
369 p = *kp;
370 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) {
371 if (i)
372 buffer[off++] = ',';
373 p.arg = arr->elem + arr->elemsize * i;
374 ret = arr->get(buffer + off, &p);
375 if (ret < 0)
376 return ret;
377 off += ret;
379 buffer[off] = '\0';
380 return off;
383 int param_set_copystring(const char *val, struct kernel_param *kp)
385 const struct kparam_string *kps = kp->str;
387 if (!val) {
388 printk(KERN_ERR "%s: missing param set value\n", kp->name);
389 return -EINVAL;
391 if (strlen(val)+1 > kps->maxlen) {
392 printk(KERN_ERR "%s: string doesn't fit in %u chars.\n",
393 kp->name, kps->maxlen-1);
394 return -ENOSPC;
396 strcpy(kps->string, val);
397 return 0;
400 int param_get_string(char *buffer, struct kernel_param *kp)
402 const struct kparam_string *kps = kp->str;
403 return strlcpy(buffer, kps->string, kps->maxlen);
406 /* sysfs output in /sys/modules/XYZ/parameters/ */
407 #define to_module_attr(n) container_of(n, struct module_attribute, attr);
408 #define to_module_kobject(n) container_of(n, struct module_kobject, kobj);
410 extern struct kernel_param __start___param[], __stop___param[];
412 struct param_attribute
414 struct module_attribute mattr;
415 struct kernel_param *param;
418 struct module_param_attrs
420 unsigned int num;
421 struct attribute_group grp;
422 struct param_attribute attrs[0];
425 #ifdef CONFIG_SYSFS
426 #define to_param_attr(n) container_of(n, struct param_attribute, mattr);
428 static ssize_t param_attr_show(struct module_attribute *mattr,
429 struct module *mod, char *buf)
431 int count;
432 struct param_attribute *attribute = to_param_attr(mattr);
434 if (!attribute->param->get)
435 return -EPERM;
437 count = attribute->param->get(buf, attribute->param);
438 if (count > 0) {
439 strcat(buf, "\n");
440 ++count;
442 return count;
445 /* sysfs always hands a nul-terminated string in buf. We rely on that. */
446 static ssize_t param_attr_store(struct module_attribute *mattr,
447 struct module *owner,
448 const char *buf, size_t len)
450 int err;
451 struct param_attribute *attribute = to_param_attr(mattr);
453 if (!attribute->param->set)
454 return -EPERM;
456 err = attribute->param->set(buf, attribute->param);
457 if (!err)
458 return len;
459 return err;
461 #endif
463 #ifdef CONFIG_MODULES
464 #define __modinit
465 #else
466 #define __modinit __init
467 #endif
469 #ifdef CONFIG_SYSFS
471 * add_sysfs_param - add a parameter to sysfs
472 * @mk: struct module_kobject
473 * @kparam: the actual parameter definition to add to sysfs
474 * @name: name of parameter
476 * Create a kobject if for a (per-module) parameter if mp NULL, and
477 * create file in sysfs. Returns an error on out of memory. Always cleans up
478 * if there's an error.
480 static __modinit int add_sysfs_param(struct module_kobject *mk,
481 struct kernel_param *kp,
482 const char *name)
484 struct module_param_attrs *new;
485 struct attribute **attrs;
486 int err, num;
488 /* We don't bother calling this with invisible parameters. */
489 BUG_ON(!kp->perm);
491 if (!mk->mp) {
492 num = 0;
493 attrs = NULL;
494 } else {
495 num = mk->mp->num;
496 attrs = mk->mp->grp.attrs;
499 /* Enlarge. */
500 new = krealloc(mk->mp,
501 sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1),
502 GFP_KERNEL);
503 if (!new) {
504 kfree(mk->mp);
505 err = -ENOMEM;
506 goto fail;
508 attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL);
509 if (!attrs) {
510 err = -ENOMEM;
511 goto fail_free_new;
514 /* Sysfs wants everything zeroed. */
515 memset(new, 0, sizeof(*new));
516 memset(&new->attrs[num], 0, sizeof(new->attrs[num]));
517 memset(&attrs[num], 0, sizeof(attrs[num]));
518 new->grp.name = "parameters";
519 new->grp.attrs = attrs;
521 /* Tack new one on the end. */
522 new->attrs[num].param = kp;
523 new->attrs[num].mattr.show = param_attr_show;
524 new->attrs[num].mattr.store = param_attr_store;
525 new->attrs[num].mattr.attr.name = (char *)name;
526 new->attrs[num].mattr.attr.mode = kp->perm;
527 new->num = num+1;
529 /* Fix up all the pointers, since krealloc can move us */
530 for (num = 0; num < new->num; num++)
531 new->grp.attrs[num] = &new->attrs[num].mattr.attr;
532 new->grp.attrs[num] = NULL;
534 mk->mp = new;
535 return 0;
537 fail_free_new:
538 kfree(new);
539 fail:
540 mk->mp = NULL;
541 return err;
544 #ifdef CONFIG_MODULES
545 static void free_module_param_attrs(struct module_kobject *mk)
547 kfree(mk->mp->grp.attrs);
548 kfree(mk->mp);
549 mk->mp = NULL;
553 * module_param_sysfs_setup - setup sysfs support for one module
554 * @mod: module
555 * @kparam: module parameters (array)
556 * @num_params: number of module parameters
558 * Adds sysfs entries for module parameters under
559 * /sys/module/[mod->name]/parameters/
561 int module_param_sysfs_setup(struct module *mod,
562 struct kernel_param *kparam,
563 unsigned int num_params)
565 int i, err;
566 bool params = false;
568 for (i = 0; i < num_params; i++) {
569 if (kparam[i].perm == 0)
570 continue;
571 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name);
572 if (err)
573 return err;
574 params = true;
577 if (!params)
578 return 0;
580 /* Create the param group. */
581 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
582 if (err)
583 free_module_param_attrs(&mod->mkobj);
584 return err;
588 * module_param_sysfs_remove - remove sysfs support for one module
589 * @mod: module
591 * Remove sysfs entries for module parameters and the corresponding
592 * kobject.
594 void module_param_sysfs_remove(struct module *mod)
596 if (mod->mkobj.mp) {
597 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp);
598 /* We are positive that no one is using any param
599 * attrs at this point. Deallocate immediately. */
600 free_module_param_attrs(&mod->mkobj);
603 #endif
605 void destroy_params(const struct kernel_param *params, unsigned num)
607 /* FIXME: This should free kmalloced charp parameters. It doesn't. */
610 static void __init kernel_add_sysfs_param(const char *name,
611 struct kernel_param *kparam,
612 unsigned int name_skip)
614 struct module_kobject *mk;
615 struct kobject *kobj;
616 int err;
618 kobj = kset_find_obj(module_kset, name);
619 if (kobj) {
620 /* We already have one. Remove params so we can add more. */
621 mk = to_module_kobject(kobj);
622 /* We need to remove it before adding parameters. */
623 sysfs_remove_group(&mk->kobj, &mk->mp->grp);
624 } else {
625 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
626 BUG_ON(!mk);
628 mk->mod = THIS_MODULE;
629 mk->kobj.kset = module_kset;
630 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL,
631 "%s", name);
632 if (err) {
633 kobject_put(&mk->kobj);
634 printk(KERN_ERR "Module '%s' failed add to sysfs, "
635 "error number %d\n", name, err);
636 printk(KERN_ERR "The system will be unstable now.\n");
637 return;
639 /* So that exit path is even. */
640 kobject_get(&mk->kobj);
643 /* These should not fail at boot. */
644 err = add_sysfs_param(mk, kparam, kparam->name + name_skip);
645 BUG_ON(err);
646 err = sysfs_create_group(&mk->kobj, &mk->mp->grp);
647 BUG_ON(err);
648 kobject_uevent(&mk->kobj, KOBJ_ADD);
649 kobject_put(&mk->kobj);
653 * param_sysfs_builtin - add contents in /sys/parameters for built-in modules
655 * Add module_parameters to sysfs for "modules" built into the kernel.
657 * The "module" name (KBUILD_MODNAME) is stored before a dot, the
658 * "parameter" name is stored behind a dot in kernel_param->name. So,
659 * extract the "module" name for all built-in kernel_param-eters,
660 * and for all who have the same, call kernel_add_sysfs_param.
662 static void __init param_sysfs_builtin(void)
664 struct kernel_param *kp;
665 unsigned int name_len;
666 char modname[MODULE_NAME_LEN];
668 for (kp = __start___param; kp < __stop___param; kp++) {
669 char *dot;
671 if (kp->perm == 0)
672 continue;
674 dot = strchr(kp->name, '.');
675 if (!dot) {
676 /* This happens for core_param() */
677 strcpy(modname, "kernel");
678 name_len = 0;
679 } else {
680 name_len = dot - kp->name + 1;
681 strlcpy(modname, kp->name, name_len);
683 kernel_add_sysfs_param(modname, kp, name_len);
688 /* module-related sysfs stuff */
690 static ssize_t module_attr_show(struct kobject *kobj,
691 struct attribute *attr,
692 char *buf)
694 struct module_attribute *attribute;
695 struct module_kobject *mk;
696 int ret;
698 attribute = to_module_attr(attr);
699 mk = to_module_kobject(kobj);
701 if (!attribute->show)
702 return -EIO;
704 ret = attribute->show(attribute, mk->mod, buf);
706 return ret;
709 static ssize_t module_attr_store(struct kobject *kobj,
710 struct attribute *attr,
711 const char *buf, size_t len)
713 struct module_attribute *attribute;
714 struct module_kobject *mk;
715 int ret;
717 attribute = to_module_attr(attr);
718 mk = to_module_kobject(kobj);
720 if (!attribute->store)
721 return -EIO;
723 ret = attribute->store(attribute, mk->mod, buf, len);
725 return ret;
728 static struct sysfs_ops module_sysfs_ops = {
729 .show = module_attr_show,
730 .store = module_attr_store,
733 static int uevent_filter(struct kset *kset, struct kobject *kobj)
735 struct kobj_type *ktype = get_ktype(kobj);
737 if (ktype == &module_ktype)
738 return 1;
739 return 0;
742 static struct kset_uevent_ops module_uevent_ops = {
743 .filter = uevent_filter,
746 struct kset *module_kset;
747 int module_sysfs_initialized;
749 struct kobj_type module_ktype = {
750 .sysfs_ops = &module_sysfs_ops,
754 * param_sysfs_init - wrapper for built-in params support
756 static int __init param_sysfs_init(void)
758 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL);
759 if (!module_kset) {
760 printk(KERN_WARNING "%s (%d): error creating kset\n",
761 __FILE__, __LINE__);
762 return -ENOMEM;
764 module_sysfs_initialized = 1;
766 param_sysfs_builtin();
768 return 0;
770 subsys_initcall(param_sysfs_init);
772 #endif /* CONFIG_SYSFS */
774 EXPORT_SYMBOL(param_set_byte);
775 EXPORT_SYMBOL(param_get_byte);
776 EXPORT_SYMBOL(param_set_short);
777 EXPORT_SYMBOL(param_get_short);
778 EXPORT_SYMBOL(param_set_ushort);
779 EXPORT_SYMBOL(param_get_ushort);
780 EXPORT_SYMBOL(param_set_int);
781 EXPORT_SYMBOL(param_get_int);
782 EXPORT_SYMBOL(param_set_uint);
783 EXPORT_SYMBOL(param_get_uint);
784 EXPORT_SYMBOL(param_set_long);
785 EXPORT_SYMBOL(param_get_long);
786 EXPORT_SYMBOL(param_set_ulong);
787 EXPORT_SYMBOL(param_get_ulong);
788 EXPORT_SYMBOL(param_set_charp);
789 EXPORT_SYMBOL(param_get_charp);
790 EXPORT_SYMBOL(param_set_bool);
791 EXPORT_SYMBOL(param_get_bool);
792 EXPORT_SYMBOL(param_set_invbool);
793 EXPORT_SYMBOL(param_get_invbool);
794 EXPORT_SYMBOL(param_array_set);
795 EXPORT_SYMBOL(param_array_get);
796 EXPORT_SYMBOL(param_set_copystring);
797 EXPORT_SYMBOL(param_get_string);